Digi 002r - HPF Switch - question

[villagechurch]

If I am using the HPF filter switch while recording acoustic and or vocals is it

necessary to use a HPF on my EQ as well...am I doubling up so to speak...?

If I have a quiet room, a silent drive, should I be enable the switch in the first place?

[promixr]

Is this the switch that is on the 002r itself? the High Pass Filter lets High Frequencies Pass and filters out low ones. So it really depends on your program material. Maybe if you were recording Barry White, you'd want to get all of the bass in his voice. So in that case you'd leave that switch off. A lot of machinery like fans and trucks driving by the studio can cause low frequencies so in that case you'd leave the switch on. It really depends on the situation. Sometimes mics have filters on them too that you can use.

In a manner of speaking, Audio Engineering is an art form that is all about learning all of the rules and then breaking them. So it would be hard to tell you what would be the 'correct way' for you without hearing the program material you are recording.

[Dan.TweekStudios]

The 002r has a highpass button on the front 4 mic pre gain knobs. Next to the input select button (mic/line). As far as how much low end it rolls off, and at what frequency it begins to roll, I'm really not sure. It might be in the manual somewhere. I almost always just leave them off. Then I use whatever EQ I'm using to roll off the lows on brighter tracks. That way you know exactly where it begins, and how much it cuts. But I would assume that if your rolling off the lows on the input signal, before it even gets to PT, that if you then put a HPF on the same track you would essentially be rolling off an already reduced low end. A little off topic, but does anyone know what the "+4 -10" switch is for on the back of the 002r next to each input? I assumed it was a +4db or -10db pad, but I'm actually getting consistently higher input levels with the switch set to "-10" and lower signals when its at "+4". Makes no sense to me... anyone shed some light?

[hooksound]

The Mic/Line/Instrument inputs on the 002r has a 75 Hz, 12 dB/octave rolloff hi-pass filter (HPF). This basically means that all frequencies below 75 Hz are cut off before the signal reaches Pro Tools. So, you can not "double the effort" by applying yet another 75Hz, 12 db/octave filter in Pro Tools, because the information is already filtered out by the hardware. However, if your mix requires the vocals to be cut at e.g. 150 Hz, or the guitar at 200 Hz, then you should of course apply a new HPF in Pro tools to cut off yet another "slice" in the bottom end.

Whether you need it or not, is a matter of taste. However, one rule of thumb is to listen and eliminate unwanted things as close to the source as possible. You can do a lot of EQ'ing by moving mics around (e.g. around the sound hole on the guitar or distance/angle to vocalists mouth). All EQs (analog or digital) adds some sort of artefacts to the signal (phase, distortion, resonance, coloration), so you should use them sparingly and if you can't do without them, it's generally better to cut than boost. But this is clinically talk. If you think it sounds right, it is right.

Happy EQ'ing.